Composite wire wrapping bit

ABSTRACT

A wire wrapping assembly includes a composite wire wrapping bit mounted in a cylindrical sleeve. The bit includes an elongated cylindrical shank member and a wear resistant, cylindrical wire wrapping head which is primarily of molded construction, as for example being formed of a pressed and sintered metal powder composition. The wire wrapping head may be connected to the shank member by a quick-releasable drive connection capable of permitting limited universal movement between the head and the shank member, and capable of imparting rotatable movement of the head in synchronism with the shank member. In the alternative, the wire wrapping head may be rigidly secured to the shank member.

United States Patent Chambers Sept. 24, 1974 COMPOSITE WIRE WRAPPING BIT Primary Examiner-Billy S. Taylor [75] Inventor. James 0. Chambers, Yukon, Okla. y Agent or Firm D D. Bosben [73] Assignee: Western Electric Company,

Incorporated, New York, NY. [57] ABSTRACT [22] Med: 1973 A wire wrapping assembly includes a composite wire [21] Appl. No.: 355,243 wrapping bit mounted in a cylindrical sleeve. The bit includes an elongated cylindrical shank member and a wear resistant, cylindrical wire wrapping head which is [52] US. Cl 242/7.06, 242/717 primarily of molded construction, as for example [51] 111i. Cl H011 43/00 being formed of a pressed and Sintered metal powder [58] Field of Search 242/706, 7.17, 7.18, 7.09; Composition The wire wrapping head may be com 140/921 124; 29/1823 nected to the shank member by a quick-releasable drive connection capable of permitting limited univer- [56] References Cted sal movement between the head and the shank mem- UNITED STATES PATENTS ber, and capable of imparting rotatable movement of 2,635,819 4 1953 Bennett 242 717 the head in synchronism with the Shank member- In 3,179,130 4/1965 Silins et al. 242/7.18 the alternative, the wire wrapping head may be rigidly 3,200,922 8/1965 Allen 242/7.l7 X secured to the shank member 3,508,717 4/1970 McCarthy et al 242/7.17 3,717,183 2/1973 Coss 140 124 10 Claims, 9 Drawing Figures COMPOSITE WIRE WRAPPING BIT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a composite wire wrapping bit, and more particularly to a composite wire wrapping bit having an elongated cylindrical shank member and a separate, wear resistance wire wrapping head which is primarily of molded construction and which preferably is quick-detachable.

2. Description of the Prior Art In the connection of insulated wires to electrical terminals in the manufacture of electrical and electronic equipment, it is standard practice to wrap stripped end portions of the wires helically about the terminals with a power hand tool. The tool includes a replaceable rotary bit which is mounted for rotation in an elongated barrel or sleeve, and the outer end of the bit has wire guiding and wrapping surfaces of special configuration for guiding and wrapping the wire onto a terminal in a series of tight helical wraps or convolutions as the bit rotates. The bit also has a longitudinally extending terminal receiving aperture in its outer end and a wire receiving slot extending longitudinally along a peripheral surface thereof and merging tangentially at its outer end with an arcuate one of the wire guiding and wrapping surfaces.

The geometry and finish of the wire guiding and wrapping surfaces of the wire wrapping bit are critical from the standpoint of achieving propr wrapping of a wire on a terminal. For example, the configuration and surface texture of the above-mentioned arcuate surface primarily determines the amount of frictional drag and tension, as well as the degree of bending which is applied to the wire during the wrapping operation. Thus, if excessive drag is exerted on the wire during the wrapping operation the wire may break or the terminal post may become twisted. On the other hand, if insufficient drag is exerted on the wire the resultant wrapped connection may be too loose and unacceptable. Accordingly, as the wire guiding and wrapping surfaces wear in operation, it eventually becomes difficult to achieve suitably wrapped connections and the wire wrapping bit must be reconditioned or replaced. This is particularly true where the wire guiding and wrapping surfaces become pitted, in which case they also may cause undesirable abrasion and scratching of the wire in the wrapping operation.

Since the advent of the power wire wrapping tools, the wire wrapping bits generally have been formed from hardened tool steels by a combination of various methods, including machining, drilling, grinding, coining and hand polishing. Since the intricate surface geometry and finish of the wire guiding and wrapping surfaces of the bits are critical and must be formed to close tolerances, frequently with the aid of a microscope, the forming of these surfaces has contributed significantly to the manufacturing costs of the bits. Further, prior known wire wrapping bits tend to wear rapidly, and to be subject to pitting and spalling, requiring frequent replacement. Accordingly, to improve the wear life and wrapping characteristics of the bits, it has been proposed, as for example in the D. R. McCarthy et al Pat. No. 3,508,717, issued Apr. 28, 1970, on a Coated Conductor Wrapping Bit, that the bits be coated with a suitable wear-resistant material. This procedure,

however, requires additional processing operations and still does not eliminate the expensive fabricating operations involved in the manufacture of the bits prior to the coating process.

In addition, another frequent problem in the use of power wire wrapping tools occurs as a result of the sleeve in which the bit rotates becoming slightly bent in the handling of the tool. As a result, the bit, which is received in the sleeve in close-fitting relationship (several thousandths of an inch), cannot rotate therein without binding. Accordingly, the sleeve must be replaced, with the removal of the bit from the sleeve frequently resulting in its being damaged to the point that it also must be replaced, even though it otherwise would have had additional useful life.

SUMMARY OF THE INVENTION In accordance with this invention, a composite wire wrapping bit which is receivable for coaxial rotation in an elongated cylindrical sleeve, includes an elongated cylindrical shank member and a cylindrical wire wrapping head which is primarily of molded construction, such as being formed of a pressed and sintered metal powder composition, and which has molded wire guiding and wrapping surfaces at one end thereof. The wire wrapping head may be connected to the shank member in axial alignment with the shank member and for rotation in synchronism therewith, by a releasable drive connection, or may be rigidly connected to the shank member. The releasable drive connection may be a tongue-and-groove coupling capable of imparting rotatable movement of the head in synchronism with the shank member, while preventing relative axial movement therebetween, with the head having a limited degree of universal movement relative to the shank member, and with the cylindrical sleeve in which the bit is mounted precluding any substantial relative lateral movement of the shank member and the head. The head and the shank member also may have aligned wire receiving slots extending longitudinally along peripheral surfaces thereof, with the slot in the head being of molded construction and merging tangentially with a molded arcuate wire guiding and wrapping surface at one end of the head.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view, partially in crosssection, of a wire wrapping tool having a composite wire wrapping bit in accordance with the invention, mounted therein;

FIG. 2 is an isometric view of a composite wire wrapping bit in accordance with the invention;

FIG. 3 is an end view of a wire wrapping head of the composite wire wrapping bit shown in FIG. 2;

FIG. 4 is an end view of a shank member of the composite wire wrapping bit shown in FIG. 2;

FIG. 5 is an enlarged end view of the bit as shown in FIG. 1, illustrating the wrapping of a wire about a terminal;

FIG. 6 is a plan view, partially in cross-section, of the bit as shown in FIG. 5;

FIG. 7 is a cross-sectional view taken substantially along the line 77 in FIG. 5;

FIG. 8 is a partial elevational view of a modified composite wire wrapping bit; and

FIG. 9 is a cross-sectional view taken along the line 9-9 in FIG. 8.

DETAILED DESCRIPTION FIG. 1 illustrates a composite wire wrapping bit 11 in accordance with the invention, mounted in a power wire wrapping tool 12 of a conventional type. The tool 12 comprises a housing 13 enclosing an air driven motor 14 and having a gripping handle 16. Compressed air is supplied to the air motor through a flexible tube 17 and the motor 14 is operated under the control of a trigger 18. The motor 14 is connected to and rotates a drive member 19, which is supported in a hollow nose member 21 extending forwardly from the housing 13 and secured thereto by a flanged nut 22.

At its forward end, the drive member 19 is provided with an axially disposed cylindrical recess for receiving one end of an elongated cylindrical shank member 23 of the composite wire wrapping bit 11. The shank member 23, and an associated wire wrapping head 24 of the composite wire wrapping bit 11, are interconnected and rotatably supported in close-fitting relationship (several thousandths of an inch) in a cylindrical sleeve or barrel 26 which extends forwardly from the nose member 21 and which is supported in a split collet 27. The collet 27 is press-fitted into the nose member 21 and carries a clamping nut 28 which may be turned for clamping the sleeve 26 thereon or releasing the sleeve therefrom.

The inner right-hand end portion of the cylindrical shank member 23, as viewed in FIGS. 1 and 2, is conventional in nature and is provided with an annular shoulder 23a which is engaged by the cylindrical sleeve 26 to hold the shank member in operating position. This end of the shank member 23 also has a notched portion 23b which cooperates with a pin 29 extending transversely across the cylindrical recess in the drive member 19 to effect a driving connection between the drive member and the shank member. Adjacent its opposite end the shank member 23 is provided with an elongated wire receiving slot 230 extending longitudinally in a peripheral surface thereof.

Similarly, the outer left-hand end of the cylindrical wire wrapping head 24, as viewed in FIGS. 1 and 2, is of conventional configuration and is provided with a longitudinally extending aperture 24a for receiving a terminal 31 during the wrapping of a wire 32 thereon in a wiring operation, as is illustrated in FIGS. 5, 6 and 7. An elongated wire receiving slot 24b extends longitudinally along a peripheral surface of the head 24 and merges tangentially with an arcuate wire guiding and wrapping surface 24c at the outer wrapping end of the head. A planar end surface 24d of the head 24 also merges tangentially with the arcuate surface 240 at its opposite end, and a forwardly projecting wiper portion 24e on the planar end surface has a curved wiping and camming surface which generally follows the periphery of the terminal receiving aperture 24a in the head, as is best shown in FIG. 5. The radius of the arcuate wire wrapping and guiding surface 24c, which is critical from the standpoint of providing proper frictional drag on the wire 32 during a wire wrapping operation, so as to produce a properly wrapped connection, is generally on the order of several hundredths of an inch and is exaggerated in the drawing for the purpose of illustration.

In accordance with this invention, the wire wrapping bit 11 is of composite construction because of the difficulty and expense involved in forming the wire wrapping end of prior known wire wrapping bits of integral one-piece construction by metal processing methods such as machining, grinding, coining and hand polishing. Specifically, the composite wire wrapping bit 11 is made in two parts, consisting of the shank member 23 and the wire wrapping head 24, with the relatively intricate head being short in comparison to the shank member so as to be of a size capable of being readily formed by a relatively inexpensive molding process, as for example, to the requisite density, hardness and straightness from a pressed and sintered metal powder composition. In this connection, it is to be understood that the term molding is being utilized in its narrower sense as meaning the forming of a part in a mold, as opposed to forming the part by processes such as the aforementioned machining, grinding and coining. The shank member 23, on the other hand, being of less complex construction, can readily be formed by conventional machining operations. The shank member 23 and the head 24 then are interconnected and mounted in the sleeve 26 of the wire wrapping tool 12, and the tool is utilized in its normal manner.

By way of illustration, the wire wrapping head 24 may be formed of a pressed and sintered metal powder composition utilizing generally known techniques. In this connection, favorable results have been achieved utilizing a composition containing iron on the order of 96.5 i 2.0 percent, carbon on the order of 0.50 $0.25 percent, nickel on the order of 1.0 percent, and one or more suitable bonding metals such as molybdenum, manganese or niobium, up to acombined amount of 2.0 percent.

The metal powder composition is compacted in a mold press (not shown) of suitable internal configuration at a pressure on the order of 50,000 psi, and subsequently sintered at 2000F for 8 /zminutes in a continuous belt-type furnace. The sintered head 24 then is restruck in a suitable die, heat treated by carburizing at 1525F in a 20-23 dew point atmosphere, quenched in oil, and drawn (heat treated) for one hour at 300F, in a conventional manner. However, to assure proper compaction of the intricate geometry of the wire wrapping head 24 adjacent its wire wrapping end, and particularly of the critical arcuate wire wrapping and guiding surface 240, the wire wrapping end of the head is formed adjacent an end of the mold press having a movable compaction member and which can be opened for withdrawal of the head after the compacting operation. Otherwise, improper compaction of the wire wrapping end of the head 24 may result and the wrapping end may crumble as it is withdrawn from the press. Similarly, to insure proper compaction, the wire wrapping end of the head 24 preferably is formed in the mold press as a solid mass, with the terminal receiving aperture 24a being formed in the head subsequent to sintering and restriking, and prior to carburizing, in a conventional drilling process.

The resultant wire wrapping head 24 is of accurate configuration and strong integral construction, and has a high surface particle hardness on the order of -62 Rockwell C scale, with long wear capability. The finish texture of the arcuate wire guiding and wrapping surface 240 also is such that it provides the necessary frictional drag on a wire to produce properly wrapped connections, and thus neither this surface, nor the wire receiving slot 24b, the planar end surface 24d or the wiper portion 24c, require any additional processing prior to placing the head 24 into use.

Referring to FIGS, 1 through 4, in use the wire wrapping head 24 is connected to the shank member 23 for rotatable movement in synchronism therewith, and so that the wire receiving slots 23c and 24b in the shank member and the head are in alignment, by a quickreleasable drive connection or coupling 33. In the disclosed embodiment of the invention, the quickreleasable drive connection 33 includes a tongue 23d (FIG. 2) on the shank member 23, having a transversely extending groove or notch 23e formed therein by machining in a conventional manner. The tongue 23d projects forward from a bearing portion 23f of the shank member 23, the bearing portion being receivable in the sleeve 26 in relatively close-fitting relationship, and the remainder of the shank member between the bearing portion and the shoulder 23a being reduced in diameter to reduce the drag between the shank member and the sleeve.

Similarly, the wire wrapping head 24 has a rearwardly projecting tongue 24f, having a transversely extending groove or notch 24g formed therein and capable of being assembled with the tongue 23d and the groove 23e on the shank member 23 in mating relationship. As in the case of the wire wrapping end of the head 24, when the head is constructed of a sintered metal powder composition as above described, to insure proper compaction of the tongue 24fit preferably is formed as a solid mass and the groove 24g is formed therein in a conventional machining operation after the sintering and restriking of the head has been completed.

The mating tongue and groove portions 23d, 23e and 24f, 24g of the quick-releasable connection 33 are formed with tolerances on the order of one or two thousandths of an inch, so that when the head and the shank member are coupled to one another they are loosely fitted together and are capable of a slight degree of universal movement therebetween. Thus, when the composite wire wrapping bit 11 is assembled in the wire wrapping sleeve 26, the bit will operate in a conventional manner, but because of the slight tolerances in the quick-releasable connection 33, and the slight internal spacing between the wire wrapping head 24 and the sleeve 26, the head will have a limited degree of floating or universal movement relative to the shank member 23 and can adapt itself to slight discrepancies in axial alignment between the bit and the sleeve, thus compensating for slight inaccuracies in the straightness of" the sleeve along its longitudinal axis.

In this regard, the provision of slight universal movement in the quick-releasable connection 33 has produced the unexpected result of the composite wire wrapping bit 11 having the capability to operate satisfactorily in the wire wrapping sleeve 26 even after the sleeve has become slightly bent during use and handling of the tool 12. This is attributed to the fact that the slight degree of universal movement of the wire wrapping head 24 on the shank member 23 permits the head to float in the sleeve 26 sufficiently to compensate for the axial misalignment of the sleeve as a result of its bent configuration, thus extneding the useful life of the sleeve and the bit 11. In contrast, in the past, with an integral one-piece wire wrapping bit, a bent sleeve normally would interfere with proper rotation of the bit in the sleeve, requiring removal of the bit and replacement of the sleeve, as well as possible replacement of the bit as a result of its also having become damaged in use or during its removal from the sleeve.

As a result of the construction ofthe quick-releasable tongue and groove connection 33, it is apparent that the wire wrapping head 24 can readily be assembled to the shank member 23, after which the assembled head and shank member can be inserted into the wire wrapping sleeve 26 for coaxial rotation therein, and the sleeve attached to the tool 12 in a conventional manner by the split collet 27 and the clamping nut 28. The tongue-and-groove connection 33 then precludes relative axial and rotatable movement of the head 24 on the shank member 23, while the sleeve prevents relative lateral movement between the head and the shank member. Similarly, the tongue-and-groove connection 33 permits quick disassembly of the wire wrapping head 24 from the shank member 23 when the head becomes worn, and the quick assembly of a new wire wrapping head to the shank member, which then may be reused.

Referring to FIGS. 5, 6 and 7, a wire wrapping operation utilizing the composite wire wrapping bit 11 is carried out in a conventional manner by initially inserting a stripped end portion of the insulated wire 32 into the wire receiving slot 24b in the wire wrapping head 24, and if the stripped portion is of sufficient length, beyond the inner end of this slot and into the wire receiving slot 23c in the shank member 23. The wire 32 then is bent rearwardly along the tool 12 and an insulated portion of the wire is positioned in a notch 26a in the sleeve 26 to anchor the wire in position relative to the sleeve during the initial portion of the wire wrapping operation. Next, the tool 12 is positioned to receive the terminal 31 in the aperture 24a in the wire wrapping head 24, and the trigger 18 is depressed to energize the tool and cause the composite wire wrapping bit 11 to I be rotated counterclockwise in the sleeve 26, as viewed in FIG. 5. As the bit 11 rotates, the wire 32 in the wire receiving slots 23c, 24b of its shank member 23 and head 24 simultaneously are wrapped about the terminal 31 and withdrawn from the slots, with the frictional drag exerted on the wire by the arcuate wire guiding and wrapping surface 240 causing the wire to be pulled into tight engagement with the terminal. At the same time, the wiper portion 24e of the head 24 sequentially engages each convolution of the wire 32 to press the convolution inwardly into firm engagement with the terminal 31, and the planar end surface 240' of the head causes the wire convolutions to be wrapped on the terminal in close-fitting engagement.

FIGS. 8 and 9 illustrate a modified form of the invention in which a wire wrapping head 24 is rigidly connected to a shank member 23' to form a composite wire wrapping bit 11'. The shank member 23 includes a forwardly extending projection 23d of noncircular configuration, as is best shown in FIG. 9. The projection 23d is receivable in a mating recess 24]" in the wire wrapping head 24', the recess having been directly formed in the head in the fabrication of the head from a metal powder composition as described above relative to the embodiment of the invention of FIGS. 17. The wire wrapping head 24 and the shank member 23 then are bonded together in axial alignment by a suitable bonding medium 34, such as silver solder or a suitable high strength adhesive. In this embodiment of the invention, however, extreme care must be taken to achieve accurate alignment of the head 24' and the shank member 23' to insure proper rotation of the resultant composite bit 11' when it is assembled in a wire wrapping sleeve. Further, when the wire wrapping head 24' becomes worn the entire bit 11 must be discarded, as compared to the embodiment of the invention in FIGS. 1-7, in which only the wire wrapping head 24 need be discarded and the shank member 23 can be reused.

While in the above-described embodiments of the invention the wire wrapping heads 24 and 24 have been described as being fabricated from a sintered metal powder composition, it is considered to be within the purview of the invention to form the wire wrapping heads in any suitable molding-type process. For example, an investment casting process could be used, in which a wax model of the wire wrapping head 24 or 24 is dipped in a ceramic slurry to form a mold, after which the wax is melted out of the mold and the mold then utilized to form the wire wrapping head by known casting techniques. Preferably, in utilizing this procedure, the entire wrapping head 24 is formed by casting except for the terminal receiving aperture 240, which is subsequently formed in a standard drilling operation. lfdesired, the shank member 23 also may be formed by casting in the same manner, providing the necessary straightness thereof is maintained.

In summary, a composite wire wrapping bit 11 or 11 has been disclosed which can be readily manufactured with significant ease and economy in comparison to prior known wire wrapping bits. Specifically, with reference to FIGS. 1-7 by way of illustration, manufacturing the wire wrapping bit 11 in two parts and subsequently connecting the parts together enables the intricate and critical geometry of the wire wrapping end of the bit, including the arcuate wire wrapping and guiding surface 24c, the wire receiving slot 24b and the planar end surface 24d which are tangential to the arcuate surface, and the wiper portion 24e, to be made conveniently by low cost manufacturing methods. For example, the wire wrapping head 24 may be made of a pressed and sintered metal powder composition by conventional techniques, to produce a part of accurate configuration, strong rigid construction, high surface hardness with long wear capability, and proper surface texture, without any appreciable additional processing being necessary.

Further, the quick-releasable connection or coupling 33 of the embodiment of the invention shown in FIGS. l-7 permits the wire wrapping head 24 to be readily replaced on the shank member 23, with the shank member being capable of reuse, thus further reducing the cost of bit replacement in comparison to prior known wire wrapping bits. In addition, providing the slight de grce of universal movement between the wire wrapping head 24 and the shank member 23 is desirable, not only because it eliminates connecting the head and the shank member in exact axial alignment with one another, but because the head can float on the shank member to accommodate itself to misalignment of the wire wrapping sleeve 26 slong its longitudinal axis. This arrangement also is advantageous because the composite bit 11 can be retained in service even after the wire wrapping sleeve 26 has become slightly bent in normal use, thus extending the useful life of the sleeve, and in many instances the life of the bit, which otherwise would have been damaged either in use in the sleeve as a result of its bent condition, or upon being removed from the bent sleeve for replacement of the sleeve.

What is claimed is:

l. A composite wire wrapping bit which is receivable for coaxial rotation in an elongated cylindrical sleeve, which comprises:

an elongated cylindrical shank member, the portion of said shank member which is receivable in the sleeve being of less length than the sleeve; and

a cylindrical wire wrapping head formed of a pressed and sintered metal powder composition and having wire guiding and wrapping surfaces at one end thereof, said wire wrapping head being short in length with respect to the portion of said shank member which is receivable in the sleeve and being connected at a second opposite end to one end of said shank member in axial alignment with said shank member and for rotation in synchronism with said shank member.

2. A composite wire wrapping bit, as recited in claim 1, wherein the connection of said short wire wrapping heaatasaa elongated shank mniBr fiibfiss:

first and second coupling means formed on the one end of said elongated shank member and the second end of said short wire wrapping head for releasably connecting said head and said shank mem' ber together and for imparting rotational movement of said head in synchronims with said shank member.

3. A composite wire wrapping bit, as recited in claim 2, in which:

said second coupling means on said short wire wrapping head is constructed to cooperate loosely with said first coupling means on said elongated shank member to permit a limited degree of universal movement of said head relative to said shank member.

4. A composite wire wrapping bit, as recited in claim 3, in which the cylindrical sleeve is of uniform internal diameter and in which:

said first and second coupling means are in the form of a tongue-and-groove connection which prevents relative axial and rotational movement of said elongated shank member and said short wire wrapping head in the cylindrical sleeve; and

said elongated shank member and said short head are received in the cylindrical sleeve in relatively closefitting relationship such that the sleeve precludes any substantial lateral movement of said shank member and said head.

5. A composite wire wrapping bit, as recited in claim 1, in which:

said short wire wrapping head is rigidly connected to said elongated shank member.

6. A wire wrapping assembly, which comprises:

an elongated cylindrical sleeve having opposite ends;

an elongated cylindrical shank member mounted for rotatable movement in said sleeve in relatively close-fitting relationship with respect to at least a portion of said sleeve, the portion of said shank member in said sleeve being of less length than the length of said sleeve;

a cylindrical wire wrapping head formed of a pressed and sintered metal powder composition mounted in said sleeve in axial alignment with said shank member and in relatively close-fitting relationship with respect to at least a portion of said sleeve; and

a releasable drive connection between said shank member and said wire wrapping head for imparting rotational movement of said head in synchronism with said shank member, said releasable drive connection being located within the confines of said sleeve between the opposite end of said sleeve.

7. A wire wrapping assembly, as recited in claim 6 in which:

said releasable drive connection is constructed so as to permit a limited degree of universal movement of said wire wrapping head in said cylindrical sleeve relative to said shank member.

8. A wire wrapping assembly, which comprises:

an elongated cylindrical sleeve;

an elongated cylindrical shank member mounted for rotatable movement in said sleeve;

a cylindrical wire wrapping head mounted in said sleeve in axial alignment with said shank member, said sleeve being of uniform internal diameter and receiving said shank member and said head in relatively close-fitting relationship so as to preclude substantial lateral movement therebetween; and

a releasable drive connection between said shank member and said wire wrapping head for imparting rotational movement of said head in synchronism with said shank member, said releasable drive connection being in the form of a tongue-and-groove coupling which prevents relative axial and rotatable movement of said shank member and said head in said sleeve.

9. A composite wire wrapping bit for use in a wire wrapping tool having a wire confining sleeve, which comprises:

a shank member fitted for rotation within the sleeve and having an end formed as a notched first coupling; and

a wire wrapping head formed of a sintered pressed metal powder composition having wear-resistant characteristics which exceed those of a bit fabricated from solid metal stock which was initially melted, solidified and then shaped into a wire wrapping bit configuration, said head having an end formed as a notched second coupling, said first and second notched couplings being dimensioned to permit a limited degree of universal movement of said head relative to said shank member when the notched couplings are mated within the sleeve to establish a driving connection between said shank member and said head.

10. A composite wire wrapping bit which is receivable for coaxial rotation in an elongated cylindrical sleeve, which comprises:

an elongated cylindrical shank member having a notched first coupling at one end thereof, the portion of said shank member which is receivable in the sleeve being of less length than the sleeve;

a cylindrical wire wrapping head of substantially molded construction and having molded wire guiding and wrapping surfaces at one end thereof, said wire wrapping head being short in length with respect to the portion of said elongated shank member which is receivable in the sleeve and having a second opposite end formed as a notched second coupling, said couplings being interconnectable within the sleeve in mating relationship to establish a driving connection between said shank member and said head for rotating said head in axial alignment and in synchronism with said shank member; and

said shank member and said wire wrapping head having aligned wire receiving slots extending longitudinally along peripheral surfaces thereof, with at least the slot in said head being of molded construction and merging tangentially with a molded arcuate wire guiding and wrapping surface at the one end of said head.

I UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTION o atentNo. 3,837,588 a Dated September 24, 1974 lnvemofls) James 0, Chambers It is certified that error appears in the above-identified oatent and that said Letters Patent are hereby corrected as shown below;

Eolumn 1, line 9, "resistance" should read -resistant--.

Column 1, line 31, "propr" should read -proper- Column 5, line 63, "extneding" should read "extending". Column 7, line 62, "slong" should read -along--. Column 8, line 23, "eomprises" should read -comprises-. Column 8, line 29,

"synchronims" should read synchronism-. Column 9, line 9, "end" should read --ends--.

Signed and gealed this r y-fiflh Of November 1975 [SEAL] Arrest:

O RUTH. MASON c. MARSHALL DANN Arresrmg Officer 7 (ummissiumr vfPaIems and Trademarks 

1. A composite wire wrapping bit which is receivable for coaxial rotation in an elongated cylindrical sleeve, which comprises: an elongated cylindrical shank member, the portion of said shank member which is receivable in the sleeve being of less length than the sleeve; and a cylindrical wire wrapping head formed of a pressed and sintered metal powder composition and having wire guiding and wrapping surfaces at one end thereof, said wire wrapping head being short in length with respect to the portion of said shank member which is receivable in the sleeve and being connected at a second opposite end to one end of said shank member in axial alignment with said shank member and for rotation in synchronism with said shank member.
 2. A composite wire wrapping bit, as recited in claim 1, wherein the connection of said short wire wrapping head to sand elongated shank member comprises: first and second coupling means formed on the one end of said elongated shank member and the second end of said short wire wrapping head for releasably connecting said head and said shank member together and for imparting rotational movement of said head in synchronims with said shank member.
 3. A composite wire wrapping bit, as recited in claim 2, in which: said second coupling means on said short wire wrapping head is constructed to cooperate loosely with said first coupling means on said elongated shank member to permit a limited degree of universal movement of said head relative to said shank member.
 4. A composite wire wrapping bit, as recited in claim 3, in which the cylindrical sleeve is of uniform internal diameter and in which: said first and second coupling means are in the form of a tongue-and-groove connection which prevents relative axial and rotational movement of said elongated shank member and said short wire wrapping head in the cylindrical sleeve; and said elongated shank member and said short head are received in the cylindrical sleeve in relatively close-fitting relationship such that the sleeve precludes any substantial lateral movement of said shank member and said head.
 5. A composite wire wrapping bit, as recited in claim 1, in which: said short wire wrapping head is rigidly connected to said elongated shank member.
 6. A wire wrapping assemBly, which comprises: an elongated cylindrical sleeve having opposite ends; an elongated cylindrical shank member mounted for rotatable movement in said sleeve in relatively close-fitting relationship with respect to at least a portion of said sleeve, the portion of said shank member in said sleeve being of less length than the length of said sleeve; a cylindrical wire wrapping head formed of a pressed and sintered metal powder composition mounted in said sleeve in axial alignment with said shank member and in relatively close-fitting relationship with respect to at least a portion of said sleeve; and a releasable drive connection between said shank member and said wire wrapping head for imparting rotational movement of said head in synchronism with said shank member, said releasable drive connection being located within the confines of said sleeve between the opposite end of said sleeve.
 7. A wire wrapping assembly, as recited in claim 6 in which: said releasable drive connection is constructed so as to permit a limited degree of universal movement of said wire wrapping head in said cylindrical sleeve relative to said shank member.
 8. A wire wrapping assembly, which comprises: an elongated cylindrical sleeve; an elongated cylindrical shank member mounted for rotatable movement in said sleeve; a cylindrical wire wrapping head mounted in said sleeve in axial alignment with said shank member, said sleeve being of uniform internal diameter and receiving said shank member and said head in relatively close-fitting relationship so as to preclude substantial lateral movement therebetween; and a releasable drive connection between said shank member and said wire wrapping head for imparting rotational movement of said head in synchronism with said shank member, said releasable drive connection being in the form of a tongue-and-groove coupling which prevents relative axial and rotatable movement of said shank member and said head in said sleeve.
 9. A composite wire wrapping bit for use in a wire wrapping tool having a wire confining sleeve, which comprises: a shank member fitted for rotation within the sleeve and having an end formed as a notched first coupling; and a wire wrapping head formed of a sintered pressed metal powder composition having wear-resistant characteristics which exceed those of a bit fabricated from solid metal stock which was initially melted, solidified and then shaped into a wire wrapping bit configuration, said head having an end formed as a notched second coupling, said first and second notched couplings being dimensioned to permit a limited degree of universal movement of said head relative to said shank member when the notched couplings are mated within the sleeve to establish a driving connection between said shank member and said head.
 10. A composite wire wrapping bit which is receivable for coaxial rotation in an elongated cylindrical sleeve, which comprises: an elongated cylindrical shank member having a notched first coupling at one end thereof, the portion of said shank member which is receivable in the sleeve being of less length than the sleeve; a cylindrical wire wrapping head of substantially molded construction and having molded wire guiding and wrapping surfaces at one end thereof, said wire wrapping head being short in length with respect to the portion of said elongated shank member which is receivable in the sleeve and having a second opposite end formed as a notched second coupling, said couplings being interconnectable within the sleeve in mating relationship to establish a driving connection between said shank member and said head for rotating said head in axial alignment and in synchronism with said shank member; and said shank member and said wire wrapping head having aligned wire receiving slots extending longitudinally along peripheral surfaces thereof, with at least the slot in said head being of molded construction and merging tangentially with A molded arcuate wire guiding and wrapping surface ath the one end of said head. 